Most efficient way to do if, else?

The IP/subnet should be added to the datagroup and then set the value for that IP and/or subnet of 2A1 or whatever the strPodNumber is. Then you can use the class command to return the corresponding value:

The datagroup will look like this in the bigip.conf:

  class private_net {
     {
        host 1.1.1.1 { "2A1" }
        network 2.2.2.0/24 { "2A1" }
        host 3.3.3.1 { "2A2" }
        network 4.4.4.0/24 { "2A2" }
     }
}

And an iRule snippet which references the class:

 Look up the server address in the dg_all_pools class and save the corresponding value
set match [class search -value dg_all_pools equals [IP::server_addr]]
if {$match ne ""}{
    do something with the match
}

Aaron